I've only been into steelheading for a year and 2 of my 6 landed fish came on a spoon. The first one was a summer run on a gold/hammered spoon with a red/orange stripe. He was hanging out near the head of a riffle behind some kings.
The second one (a chromer) was on Christmas eve in the tailout of a very long run. I was using a silver/hammered (love hammered spoons) spoon (one of those ones from fred meyer - Rainbow brand I think).

I've been fishing for trout for years and spoons are one of my favorite lures. I also had a lot of kings hit them while trout fishing. I like the kind that are more of a long teardrop - think of a slightly stretched steel-lee.

I do try added lead once in a while, but I think it makes me reel it in too fast to avoid hang-ups. In fast water, I cast a little upstream, reel in the slack, and begin putting pressure on it as soon as I feel the first tick. Then I keep just enough pressure on it to tick the bottom (or the bigger rocks) about every 10 to 20 ft. As it gets down below me, I slow it down even more, and throw in a little jigging (quickly dropping the tip) on the swing and as I bring it in on a slow retrieve. Like swinging a steelhead fly, try to let is hang down stream for a few seconds (after the swing), just fluttering, and maybe a few small jigging motions, before you bring it in.
Another thing, it's tempting to cast to the best water first. Try hard to focus on the water closest to you then work your way out.

Good luck!